Holmes pleaded not guilty by reason of insanity to charges of killing 12 people and wounding 70 others in the July 2012 attack. Prosecutors are looking for any evidence, such as emails, that might show signs of rationality that would undermine the insanity defense.

The defense is trying to block the emails, as well as statements Holmes made to police and evidence seized from his car, computers and iPhone.

At a pretrial hearing Friday, defense attorneys said the affidavits and court orders used to obtain the emails were so broad they swept up some emails that merely mentioned Holmes but weren't sent to or from his accounts.

Prosecutors said the requests had to be broad because investigators initially didn't know if Holmes had accomplices.

Investigators obtained Holmes' emails from Google, Microsoft and the University of Colorado. Holmes had been a graduate student in neuroscience at the university's Denver campus, but he had academic problems and dropped out before the shootings.

The university released thousands of emails in December in response to media requests about Holmes under the state open records law. Many were heavily redacted, and they provided little information on Holmes' struggles at the school.

Holmes' Gmail and Hotmail emails haven't been made public.

Holmes, now 25, is accused of opening fire in a movie theater in the Denver suburb of Aurora where more than 400 people were watching a midnight showing of a Batman movie.

His trial is scheduled to start in February. Prosecutors are seeking the death penalty.

Arapahoe County Judge Carlos A. Samour Jr. hasn't said when he will rule on whether the emails, statements and other evidence can be used.

Even if he excludes the evidence, prosecutors still have a strong case, legal analysts say. Holmes' attorneys have acknowledged he was the shooter, but they say he was in the midst of a psychotic episode.